Seat and back support cushions having contoured support surfaces are highly desirable for various reasons. For example, seating surfaces contoured and dimensioned for the individual user allow for a more uniform spreading over the entire seating surface of the user's weight for increased comfort. In the case of a wheelchair-bound user, the added comfort of a contoured seating surface is evidenced in substantially reduced likelihood of the formation of pressure sores. Contoured seating surfaces also may provide lateral support which may be particularly important for the infirm or handicapped.
The prior art includes various approaches for fabricating individually contoured seat and back support cushions. U.S. Pat. Nos. 4,615,856, issued Oct. 7, 1986, and 4,525,130, issued June 25, 1985, disclose apparatus for forming an individually contoured seat such as for a wheelchair employing flexible, sealed, bead-filled seat and back bags which are evacuated while the person being fitted is seated thereon to form a fixed impression of the person's support surfaces. Positive molds of the individual's support surfaces are then made, with the positive mold impression then utilized in cooperation with a molding frame to mold custom-fitted seat and back cushions which are particularly adapted for mounting in a wheelchair.
It is frequently not necessary to provide support cushions which are custom contoured in accordance with the dimensions and configuration of the user. For example, where the intended user does not suffer from a deformity, a cushion contoured in accordance with standard dimensions and configurations may be equally suitable at a much reduced cost. The use of contoured support cushions having a range of standard sizes for wheelchair use in one of several standard contoured support surfaces are becoming increasingly popular. This is particularly true in the case of children who do not suffer from a degenerative condition. In this case, it is highly desirable to fit the child with a standard contoured support cushion which may be replaced with a larger cushion at reasonable cost as the child grows.
Although the standard contoured support cushion is becoming increasingly popular, difficulties in making accurate measurements for a proper fitting of the cushion remain. While there are techniques and devices available for accurately measuring the circumference of anatomical members, it is difficult to accurately measure linear dimensions of various body parts. This difficulty is primarily due to the non-linear nature of most body parts because surfaces along which measurements are taken are typically curved and somewhat irregular. A shoe gauge is an example of one device which has been used to take such measurements, but such devices are limited in application to measuring the relatively linear dimensions of the human foot. Accurately measuring the seating support dimensions of a person being fitted with a standard back or seat support cushion has therefore been a problem and frequently results in improper cushion fitting.